Self-discharge

There seems to be this USB charging cable different versions.
In my plug is transparent and when plugging (battery empty) a bright red LED, which is not to be overlooked is illuminated. If the LED turns off, the battery is full.
The first store I had my Heli charged using the USB port of the laptop and leave the cable including Heli on laptop after switching off of the laptop. Of course that was unintentional.
The result was that the battery was empty in the morning, so obviously had the electronics in the USB cable, the power consumed again (or the laptop has become loaded with the Heli-battery; -) ...)

No offense, but this is of course unacceptable, especially here in the missing manual is also nothing about it.

Nevertheless I forgive 3 stars because the cable usually done good service. Now I use it exclusively to a USB power supply and make sure that I safety's sake the connection immediately release when the battery is full, what are the Zoopa 150 little more than 10 minutes, significantly less than using the remote control.
Costs should be in play in theory, because the batteries of the transmitter must be indeed buy and their consumption is fierce ...

EDIT after about 8 months:
Sorry to deduct a star for loose contact, which occurred after about 8 months. In other words: cable still funzt but only limited.